308 Tuberculosis 



what and are not attached to each other. Organisms found 

 in old pus and sputum show a peculiar beaded appearance 

 caused by fragmentation of the protoplasm and the presence 

 of metachromatic granules (Fig. 89). These fragmented 



: 



' & / ~*~*-* '* 



Fig. 89. Tubercle bacillus in sputum (Frankel and Pfeiffer). 



forms have been thought to be bacilli in the stage of spor- 

 ulation (see Fig. 90), and Koch originally held this view 

 himself, though later researches have not confirmed it. 



Fig. 90. Tubercle bacilli: 1, Forms suggesting sporulation, because 

 of the presence of large chromophilic granules ; 2, forms described as 

 beaded; the open spaces in the fragmented rods are sometimes mis- 

 taken for spores ; 3, branched forms of the tubercle bacillus sometimes 

 seen in sputum. 



The tubercle bacillus forms no endospores. The frag- 

 ments thought by Koch to be spores are irregular in shape, 

 have ragged surfaces, and are without the high refraction 



